Spark plug



. c. HouaH.

SPARK PLUG.

APPLICATION FILED FEB. 21, 1920.

Patented Apr. 18, 192.2.

CLAYTON ROUGH, or A'Too, NEW JERSEY.

SPARK rime.'

Leraars.

Application filed February 27,1920. Serial No. 361,619.y

To ZZ whom-'it may concern:

Be it known that I, CLAYTON Hout-ui, a

citizen of the United States, residing at 'Improvements in Spark Plugs,of which the following is a specication.

My invention relates to a new and useful improvement in spark plugs, andhas for its object to so construct such a plug as to provide for theaccurate adjustment of the spark gap.

With this end in view, this invention consists in the details ofconstruction and combination of elements hereinafter set vforth and thenspecifically designated [by the claim.

In order that those skilled in the art to which this inventionappertains, may understand how to make and useV the same, 1 willdescribe its construction in detail, referring by numerals to theaccompanying drawing forming a part of this application, in which Fig.1, is a side elevation of a plug hav-l ing my improvement embodiedtherein, a portion being broken away and sectioned so as to clearly showthe construction of the adjusting mechanism.

Fig. 2, is an end view ofFig. llooking upward.

Fig. 3, is an enlarged view of the lowerV portion of Fig. 1. a

Fig. 4, is a bottom plan view of a slightly modified form of theadjustable member.

Fig. 5, is a centralsection of Fig. 4, andv Fig. 6, is a side elevationof Fig. 4.

ln carrying out my invention as here enibodied, l represents a sparkplug of usual construction havingthe threaded shank 2 for securement inthe head of a cylinder ofl an internal combustion engine, the lower endof this shank is reduced in diameter to form the hub 3 which isexternally threaded. Y

has been properly adjusted, thus holding` this collar against.accidental displacement. 7 represents the stem, the lower end of whichforms the spark gap extremity of the positive side of the circuit, andacross the ower end of this stem extends the bridge wire 5 so that whenthe collar 4 is screwed up or down upon the hub 3 this bridge wire willbe brought closer to or removed further from the lower end of the stem,thus lessening or increasing the spark gap as described, and when theproper adjustment of the spark gap has been thus secured the jam nut 6is vrmly set against thecollar so as to maintain this adjustment.

Heretofore the adjustment of the spark` gap wires has been eected lbybending thesame back and forth which seldom produced satisfactoryresults and loosen the wires Vin their fastenings, but by my improvementthese disadvantages are entirely overcome, as the bridge wire isVadjusted bodily to and .from the lower'end of the stem with greataccuracy'on account of running thezcollar which `carries said wireV uponthethreaded in, but for most purposes I prefer that 'the adjustablemember may be made entirely in one piece so as'to prevent thelooseningof the wirestherein on account of the changel of temperature when theplug is in use, yand I have shown Ysuch a construction in Figs. 4, 5 and6. In this last named construction the adjusting member consists 'of thebody 3 having formed therewith the bridge 9 Vthe Vbody being internallyVthreaded as indicated at l0. This form of adjusting memberls cheap tomanufacture since the body may be drawn up. in the form of a shallowshell and the bridge produced by milling away a portion of the sides ofsaid shell leaving the bridge. v

Ofcourse I do not wish toY be limited to the exact details ofconstruction as "herein shown as these may be varied within ythe limitsof the appended claimy without departing from the spirit of myinvention.

Having thus fully described niyzinvention, Y

In combination, a Yspark plug including Y the ordinary threaded shankand having Va s temror electrode projecting therefrom, an externallythreaded hub formed with said spark plug of less diameter than theshank,

be adjustable relative thereto when the eollar Carrying the same isadjusted upon its hub.

In testimony whereof, have hereunto af-- fixed my signature.

CLAYTON HOUGH.

